DESCRIPTION: The proposed research is aimed at working out the molecular mechanisms that govern fat-specific gene expression as part of cellular differentiation in the mouse. Much of the proposal concerns stearoyl-CoA desaturase gene 1 (SCD1) regulation in adipose and liver tissue or cell lines. SCD1 is transcriptionally activated during preadipocyte differentiation and is regulated differently by insulin, carbohydrates and fatty acids. The applicant wishes to define the genetic elements associated with the gene as well as several regulatory proteins proposed to mediate the various mechanisms of regulation. He will, in addition, carry out experiments aimed at determining the mechanism through which arachidonic acid inhibits adipocyte differentiation.